Revised Pacific-Antarctic plate motions and geophysics of the Menard Fracture Zone

A reconnaissance survey of multibeam bathymetry and magnetic anomaly data of the Menard Fracture Zone allows for significant refinement of plate motion history of the South Pacific over the last 44 million years. The right-stepping Menard Fracture Zone developed at the northern end of the Pacific-Antarctic Ridge within a propagating rift system that generated the Hudson microplate and formed the conjugate Henry and Hudson Troughs as a response to a major plate reorganization ∼45 million years ago. Two splays, originally about 30 to 35 km apart, narrowed gradually to a corridor of 5 to 10 km width, while lineation azimuths experienced an 8° counterclockwise reorientation owing to changes in spreading direction between chrons C13o and C6C (33 to 24 million years ago). We use the improved Pacific-Antarctic plate motions to analyze the development of the southwest end of the Pacific-Antarctic Ridge. Owing to a 45° counterclockwise reorientation between chrons C27 and C20 (61 to 44 million years ago) this section of the ridge became a long transform fault connected to the Macquarie Triple Junction. Following a clockwise change starting around chron C13o (33 million years ago), the transform fault opened. A counterclockwise change starting around chron C10y (28 millions years ago) again led to a long transform fault between chrons C6C and C5y (24 to 10 million years ago). A second period of clockwise reorientation starting around chron C5y (10 million years ago) put the transform fault into extension, forming an array of 15 en echelon transform faults and short linking spreading centers

Invited perspectives: Mountain roads in Nepal at a new crossroads

In Nepal and many developing countries around the world, roads are vehicles for development for communities in rural areas. By reducing travel time on foot, opportunities are opened for quicker transportation of goods and better access to employment, education, health care and markets. Roads also fuel migration and numerous social changes, both positive and negative. Poorly constructed roads in mountainous areas of Nepal have increased erosion and landslide risk as they often cut through fragile geology, destabilizing slopes and altering local hydrological conditions, with costs to lives and livelihoods. The convergence of the newly constituted decentralized Nepali government with China's Belt and Road Initiative is likely to bring more roads to rural communities. The new provincial government administrations now have the opportunity to develop policies and practices, which can realign the current trend of poorly engineered, inefficient and hazardous road construction toward a more sustainable trajectory. This commentary provides an overview of some of the obstacles along the way for a more sustainable road network in Nepal and illustrates how good governance, development and landslide risk are intertwined. The opinion presented in this brief commentary lends little hope that Nepal's current pathway of unsustainable road construction will provide the country with the much-needed sustainable road network, unless checks and balances are put in place to curb noncompliance with existing laws and policies.</p

Omicron neutralising antibodies after COVID-19 vaccination in haemodialysis patients.

Funder: Kidney Research U

The Improved Kidney Risk Score in ANCA-Associated Vasculitis for Clinical Practice and Trials

Background Reliable prediction tools are needed to personalize treatment in ANCA-associated GN. A retrospective international longitudinal cohort was collated to revise the ANCA renal risk score. Methods The primary end point was ESKD with patients censored at last follow-up. Cox proportional hazards were used to reweight risk factors. Kaplan–Meier curves, Harrell’s C statistic, receiver operating characteristics, and calibration plots were used to assess model performance. Results Of 1591 patients, 1439 were included in the final analyses, 2:1 randomly allocated per center to development and validation cohorts (52% male, median age 64 years). In the development cohort (n5959), the ANCA renal risk score was validated and calibrated, and parameters were reinvestigated modifying interstitial fibrosis and tubular atrophy allowing semiquantitative reporting. An additional cutoff for kidney function (K) was identified, and serum creatinine replaced GFR (K0:,250 mmol/L50, K1: 250–450 mmol/L54, K2: .450 mmol/L511 points). The risk points for the percentage of normal glomeruli (N) and interstitial fibrosis and tubular atrophy (T) were reweighted (N0: .25%50, N1: 10%–25%54, N2:,10%57, T0: none/mild or,25%50, T1: $mild-moderate or$25%53 points), and four risk groups created: low (0–4 points), moderate (5–11), high (12–18), and very high (21). Discrimination was C50.831, and the 3-year kidney survival was 96%, 79%, 54%, and 19%, respectively. The revised score performed similarly well in the validation cohort with excellent calibration and discrimination (n5480, C50.821). Conclusions The updated score optimizes clinicopathologic prognostication for clinical practice and trials.</p

Multidimensional Model of Racial Identity: A Reconceptualization of African American Racial Identity

Research on African American racial identity has utilized 2 distinct approaches. The mainstream approach has focused on universal properties associated with ethnic and racial identities. In contrast, the underground approach has focused on documenting the qualitative meaning of being African American, with an emphasis on the unique cultural and historical experiences of African Americans. The Multidimensional Model of Racial Identity (MMRI) represents a synthesis of the strengths of these two approaches. The underlying assumptions associated with the model are explored. The model proposes 4 dimensions of African American racial identity: salience, centrality, regard, and ideology. A description of these dimensions is provided along with a discussion of how they interact to influence behavior at the level of the event. We argue that the MMRI has the potential to make contributions to traditional research objectives of both approaches, as well as to provide the impetus to explore new questions.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68695/2/10.1207_s15327957pspr0201_2.pd

Immune responses following 3rd and 4th doses of heterologous and homologous COVID-19 vaccines in kidney transplant recipients

Background Solid organ transplant recipients have attenuated immune responses to SARS-CoV-2 vaccines. In this study, we report on immune responses to 3rd- (V3) and 4th- (V4) doses of heterologous and homologous vaccines in a kidney transplant population. Methods We undertook a single centre cohort study of 724 kidney transplant recipients prospectively screened for serological responses following 3 primary doses of a SARS-CoV2 vaccine. 322 patients were sampled post-V4 for anti-spike (anti-S), with 69 undergoing assessment of SARS-CoV-2 T-cell responses. All vaccine doses were received post-transplant, only mRNA vaccines were used for V3 and V4 dosing. All participants had serological testing performed post-V2 and at least once prior to their first dose of vaccine. Findings 586/724 (80.9%) patients were infection-naïve post-V3; 141/2586 (24.1%) remained seronegative at 31 (21-51) days post-V3. Timing of vaccination in relation to transplantation, OR: 0.28 (0.15-0.54), p=0.0001; immunosuppression burden, OR: 0.22 (0.13-0.37), p<0.0001, and a diagnosis of diabetes, OR: 0.49 (0.32-0.75), p=0.001, remained independent risk factors for non-seroconversion. Seropositive patients post-V3 had greater anti-S if primed with BNT162b2 compared with ChAdOx1, p=0.001. Post-V4, 45/239 (18.8%) infection-naïve patients remained seronegative. De novo seroconversion post-V4 occurred in 15/60 (25.0%) patients. There was no difference in anti-S post-V4 by vaccine combination, p=0.50. T-cell responses were poor, with only 11/54 (20.4%) infection-naive patients having detectable T-cell responses post-V4, with no difference seen by vaccine type. Interpretation A significant proportion of transplant recipients remain seronegative following 3- and 4- doses of SARS-CoV-2 vaccines, with poor T-cell responses, and are likely to have inadequate protection against infection. As such alternative strategies are required to provide protection to this vulnerable group. Funding MW/PK received study support from Oxford Immunotec

Large-scale mass wasting in the western Indian Ocean constrains onset of East African rifting

Faulting and earthquakes occur extensively along the flanks of the East African Rift System, including an offshore branch in the western Indian Ocean, resulting in remobilization of sediment in the form of landslides. To date, constraints on the occurrence of submarine landslides at margin scale are lacking, leaving unanswered a link between rifting and slope instability. Here, we show the first overview of landslide deposits in the post-Eocene stratigraphy of the Tanzania margin and we present the discovery of one of the biggest landslides on Earth: the Mafia mega-slide. The emplacement of multiple landslides, including the Mafia mega-slide, during the early-mid Miocene is coeval with cratonic rifting in Tanzania, indicating that plateau uplift and rifting in East Africa triggered large and potentially tsunamigenic landslides likely through earthquake activity and enhanced sediment supply. This study is a first step to evaluate the risk associated with submarine landslides in the region